Refining ammonia inventories through top-down inverse modelling in high-density swine farming regions
摘要
The accurate estimation of ammonia (NH3) emissions from livestock facilities is required to establish effective air quality management policies, yet significant uncertainty remains in current bottom-up inventories. This study thus presents a top-down inverse modelling approach for the estimation of NH3 emission factors. We validated the performance of three atmospheric dispersion models—AERMOD, CALPUFF, and computational fluid dynamics (CFD)—against atmospheric NH3 datasets collected over four seasons in a high-density pig farming region with aging, older-type facilities in South Korea. Evaluation of model performance revealed that the CFD model produced the most accurate local concentration distributions, with an index of agreement (IA) of 0.98, while CALPUFF effectively captured long-term temporal variation (IA = 0.89). Based on the CALPUFF results, the average NH3 emission factor was estimated to be 4.17